According to the curved surface processing, the lens can be divided into spherical lens and aspheric lens.

(1) Spherical lens

Spherical lens, the two sides of the lens are spherical arcs. When light of different wavelengths is incident on a parallel optical axis at different positions on the lens, it cannot be focused to a point on the plane, which causes aberration problems and affects the quality of the image. , The objects seen around the lens are distorted, which limits the vision of the wearer.

(2) Aspherical lens

The surface curvature of the aspheric lens is different from that of the ordinary spherical lens. In order to pursue the thinness of the lens, the curved surface of the lens needs to be changed. In the past, the spherical design and aspheric design were used to correct the image and solve the problem of distortion of the field of view. At the same time, the lens is more Lighter, thinner and flatter. Moreover, it still maintains excellent impact resistance, allowing the wearer to use it safely.